For this case our reference triangle is ABC and we want to describe what we need to do in order to obtain the triangle DEF
And for this case we can use the coordinate of A and F as reference
A=(2,5)
B=(15,3)
And we can find the transformation on this way:
So we can move the triangle 13 units to the right and 2 units down respect to the A coordinate and we will get the result of the triangle DEF